Rituximab in non-systemic vasculitic neuropathy: a single-center experience

OBJECTIVES

This case series reports clinical features and outcome of four patients with non-systemic vasculitic neuropathy (NSVN) treated with the anti-CD20 agent rituximab.

METHODS

Clinical, electrophysiological and biopsy data were retrospectively obtained and evaluated. Only patients with pathological definite or probable NSVN were included. Extensive clinical and laboratory work-up excluded systemic vasculitis. Follow-up data for at least 12 months and up to five years is provided. Outcome of the patients was assessed using the MRC-Sum Score, Prineas Score and Neurological Symptom Score.

RESULTS

Two of four patients treated with rituximab achieved disease remission and one patient remained stable under anti-CD20 therapy after a required treatment switch due to toxic side effects of cyclophosphamide. One patient deteriorated under rituximab induction. Rituximab was well tolerated in all patients.

DISCUSSION

Anti-CD20 therapy might be an alternative in NSVN patients requiring further treatment escalation or treatment switch due to side effects of corticosteroids or cyclophosphamide.

Comparative analysis of albumin quotient and total CSF protein in immune-mediated neuropathies: a multicenter study on diagnostic implications

Introduction

Blood-cerebrospinal fluid (CSF) barrier dysfunction is pivotal for diagnosing immune-mediated neuropathies, especially in spinal nerve root inflammation. Typically, either total CSF protein or the CSF to serum albumin ratio (QAlb) is measured. Total CSF protein measurements have limitations, notably its fixed reference value regardless of age, in contrast to the age-dependent reference for QAlb. Our goal was to evaluate both markers in patients with immune-mediated neuropathies.

Methods

In our multicenter research, we collected retrospective CSF data from patients suffering from immune-mediated neuropathies across four German research centers. These parameters were analyzed in relation to their clinical characteristics.

Results

Out of 419 samples, 36 (8.6%) displayed a notable variation between total CSF protein and QAlb values. A detailed analysis revealed that patients displaying elevated QAlb but normal total CSF protein levels were significantly younger at disease onset (p = 0.01), at the time of diagnosis (p = 0.005), and when undergoing lumbar puncture (p = 0.001) compared to patients with elevated CSF protein and normal QAlb levels. These effects were especially evident for the subgroup of samples derived by female patients.

Discussion

Our work confirms the crucial role of QAlb in diagnosing immune-mediated neuropathies and particularly its efficacy as a marker for evaluating the blood-CSF barrier in patients with an earlier disease onset. Considering the significance of the albumin quotient, its assessment is especially advisable in younger patients of female sex to avoid missing a potential barrier dysfunction that might be falsely negative when using total protein.

Immunomodulatory effects of intravenous and subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy: An observational study

BACKGROUND AND PURPOSE

It is not known whether the route of administration affects the mechanisms of action of therapeutic immunoglobulin in chronic inflammatory demyelinating polyneuropathy (CIDP). The aim of this study, therefore, was to compare the immunomodulatory effects of intravenous (IVIg) and subcutaneous immunoglobulin (SCIg) in patients with CIDP and in IVIg-treated common variable immunodeficiency (CVID) patients.

METHODS

Serum and peripheral blood mononuclear cell samples were obtained from 30 CIDP patients receiving IVIg, 10 CIDP patients receiving SCIg, and 15 patients with CVID receiving IVIg. Samples and clinical data were obtained prior to IVIg/SCIg and at 3 days, 7 days, and, in CIDP patients receiving IVIg, 21 days post-administration. Serum cytokines were assessed by Luminex-based multiplex assay and enzyme-linked immunosorbent assay. Immune cells were characterized by flow cytometry.

RESULTS

Immune cell profiles of CIDP and CVID patients differed in frequencies of myeloid dendritic cells and cytotoxic natural killer cells. During treatment with IVIg or SCIg in CIDP patients, cellular immunomarkers were largely similar. CIDP patients receiving IVIg had higher macrophage inflammatory protein (MIP)-1α (p = 0.01), interleukin (IL)-4 (p = 0.04), and IL-33 (p = 0.04) levels than SCIg recipients. IVIg treatment more broadly modulated cytokines in CIDP than SCIg treatment.

CONCLUSIONS

Our study demonstrates that the modulation of cellular immunomarkers in CIDP is independent of the application route of therapeutic immunoglobulin. Minor differences were observed between CIDP and CVID patients. In contrast, cytokines were differentially modulated by IVIg and SCIg in CIDP.

2,4-Dinitrophenol does not exert neuro-regenerative potential in experimental autoimmune neuritis

OBJECTIVE

We evaluated the potential neuro-regenerative effects of the mitochondrial uncoupler 2,4-Dinitrophenol in experimental autoimmune neuritis, an animal model for an acute autoimmune neuropathy.

METHODS

Experimental autoimmune neuritis was induced in Lewis rats. Different concentrations of 2,4-Dinitrophenol (1 mg/kg, 0.1 mg/kg and 0.01 mg/kg) were applied during the recovery phase of the neuritis (at days 18, 22 and 26) and compared to the vehicle. Any effects were assessed through functional, electrophysiological, and morphological analysis via electron microscopy of all groups at day 30. Additional immune-histochemical analysis of inflammation markers and remyelination of the sciatic nerves were performed for the dosage of 1 mg/kg and control.

RESULTS

No enhancement of functional or electrophysiological recovery was observed in all 2,4-Dinitrophenol-treated groups. Cellular inflammation markers of T cells (CD3+) were comparable to control, and an increase of macrophages (IbA1+) invasion in the sciatic nerves was observed. Treatment with 2,4-Dinitrophenol reduced axonal swelling in myelinated and unmyelinated fibers with an increased production of brain-derived neurotrophic factor.

CONCLUSION

Our findings do not support the hypothesis that repurposing of the mitochondrial uncoupler 2,4-Dinitrophenol exerts functionally relevant neuro-regenerative effects in autoimmune neuritis.

Prognosis and management of acute symptomatic seizures: a prospective, multicenter, observational study

BACKGROUND

Acute symptomatic epileptic seizures are frequently seen in neurocritical care. To prevent subsequent unprovoked seizures, long-term treatments with antiseizure medications are often initiated although supporting evidence is lacking. This study aimed at prospectively assessing the risk of unprovoked seizure relapse with respect to the use of antiseizure medications. It was hypothesized that after a first acute symptomatic seizure of structural etiology, the cumulative 12-month risk of unprovoked seizure relapse is ≤ 25%.

METHODS

Inclusion criteria were age ≥ 18 and acute symptomatic first-ever epileptic seizure; patients with status epilepticus were excluded. Using telephone and mail interviews, participants were followed for 12 months after the acute symptomatic first seizure. Primary endpoint was the occurrence and timing of a first unprovoked seizure relapse. In addition, neuro-intensivists in Germany were interviewed about their antiseizure treatment strategies through an anonymous online survey.

RESULTS

Eleven of 122 participants with structural etiology had an unprovoked seizure relapse, resulting in a cumulative 12-month risk of 10.7% (95%CI, 4.7%-16.7%). None of 19 participants with a non-structural etiology had a subsequent unprovoked seizure. Compared to structural etiology alone, combined infectious and structural etiology was independently associated with unprovoked seizure relapse (OR 11.1; 95%CI, 1.8-69.7). Median duration of antiseizure treatment was 3.4 months (IQR 0-9.3). Seven out of 11 participants had their unprovoked seizure relapse while taking antiseizure medication; longer treatment durations were not associated with decreased risk of unprovoked seizure relapse. Following the non-representative online survey, most neuro-intensivists consider 3 months or less of antiseizure medication to be adequate.

CONCLUSIONS

Even in case of structural etiology, acute symptomatic seizures bear a low risk of subsequent unprovoked seizures. There is still no evidence favoring long-term treatments with antiseizure medications. Hence, individual constellations with an increased risk of unprovoked seizure relapse should be identified, such as central nervous system infections causing structural brain damage. However, in the absence of high-risk features, antiseizure medications should be discontinued early to avoid overtreatment.

Motor unit number estimation by MScanFit in myotonic dystrophies

BACKGROUND

MScanFit is a new motor unit number estimation (MUNE) technique applied in motor neuron diseases and polyneuropathies to assess clinical progression and underlying disease pathology. So far, its value in myopathies, especially myotonic dystrophies (MD), has not been investigated.

METHODS

Motor unit loss and characteristics of patients with genetically confirmed MD type 1 (n = 7) and type 2 (n = 5) were investigated using MScanFit of the abductor pollicis brevis muscle and compared to age-matched healthy controls. MUNE measures were correlated with muscle impairment determined by the MRC sum score and handgrip strength.

RESULTS

MScanFit detected motor unit loss in patients with MD (p = 0.017). There was no significant difference in motor unit loss between MD type 1 and type 2 (p = 0.64). CMAP-discontinuities which, when added up, exceed 50% of the CMAP amplitude were reduced in MD patients (p = 0.0284), but motor unit amplitudes were not significantly different (p = 0.0597). The motor unit loss strongly correlated with the MRC sum score (p = 0.014, Rho = 0.678).

CONCLUSIONS

Our study shows the feasibility of MScanFit in MD and its potential to serve as a surrogate marker for overall muscle impairment. Motor unit analysis indicates that neurogenic alterations in both MD subtypes might be present.

Prehospital Levetiracetam Use in Adults With Status Epilepticus: Results of a Multicenter Registry

BACKGROUND AND PURPOSE

Status epilepticus (SE) is a neurological emergency due to prolonged seizure activity or multiple seizures without full recovery in between them. Prehospital SE management is crucial since its duration is correlated with higher morbidity and mortality rates. We examined the impact of different therapeutic strategies in the prehospital setting with a focus on levetiracetam.

METHODS

We initiated the Project for SE in Cologne, a scientific association of all neurological departments of Cologne, the fourth-largest city in Germany with around 1,000,000 inhabitants. All patients with an SE diagnosis were evaluated over 2 years (from March 2019 to February 2021) to determine whether prehospital levetiracetam use had a significant effect on SE parameters.

RESULTS

We identified 145 patients who received initial drug therapy in the prehospital setting by professional medical staff. Various benzodiazepine (BZD) derivatives were used as first-line treatments, which were mostly used in line with the recommended guidelines. Levetiracetam was regularly used (n=42) and mostly in combination with BZDs, but no significant additional effect was observed for intravenous levetiracetam. However, it appeared that the administered doses tended to be low.

CONCLUSIONS

Levetiracetam can be applied to adults with SE in prehospital settings with little effort. Nevertheless, the prehospital treatment regimen described here for the first time did not significantly improve the preclinical cessation rate of SE. Future therapy concepts should be based on this, and the effects of higher doses should in particular be reexamined.

Kinesin-5 inhibition improves neural regeneration in experimental autoimmune neuritis

BACKGROUND

Autoimmune neuropathies can result in long-term disability and incomplete recovery, despite adequate first-line therapy. Kinesin-5 inhibition was shown to accelerate neurite outgrowth in different preclinical studies. Here, we evaluated the potential neuro-regenerative effects of the small molecule kinesin-5 inhibitor monastrol in a rodent model of acute autoimmune neuropathies, experimental autoimmune neuritis.

METHODS

Experimental autoimmune neuritis was induced in Lewis rats with the neurogenic P2-peptide. At the beginning of the recovery phase at day 18, the animals were treated with 1 mg/kg monastrol or sham and observed until day 30 post-immunisation. Electrophysiological and histological analysis for markers of inflammation and remyelination of the sciatic nerve were performed. Neuromuscular junctions of the tibialis anterior muscles were analysed for reinnervation. We further treated human induced pluripotent stem cells-derived secondary motor neurons with monastrol in different concentrations and performed a neurite outgrowth assay.

RESULTS

Treatment with monastrol enhanced functional and histological recovery in experimental autoimmune neuritis. Motor nerve conduction velocity at day 30 in the treated animals was comparable to pre-neuritis values. Monastrol-treated animals showed partially reinnervated or intact neuromuscular junctions. A significant and dose-dependent accelerated neurite outgrowth was observed after kinesin-5 inhibition as a possible mode of action.

CONCLUSION

Pharmacological kinesin-5 inhibition improves the functional outcome in experimental autoimmune neuritis through accelerated motor neurite outgrowth and histological recovery. This approach could be of interest to improve the outcome of autoimmune neuropathy patients.

CIDP: Analysis of Immunomarkers During COVID-19 mRNA-Vaccination and IVIg-Immunomodulation: An Exploratory Study

Availability of COVID-19 mRNA vaccine for patients with chronic inflammatory demyelinating polyneuropathy (CIDP) treated with intravenous immunoglobulin (IVIg) raises the question of whether COVID-19 mRNA vaccine influences disease activity or IVIg-mediated immunomodulation in CIDP. In this exploratory study, blood samples of CIDP patients on IVIg treatment were longitudinally analyzed before and after vaccination with a COVID-19 mRNA vaccine. A total of 44 samples of eleven patients were characterized at four timepoints by ELISA and flow cytometry in terms of immunomarkers for disease activity and IVIg-immunomodulation. Apart from a significantly lower expression of CD32b on naïve B cells after vaccination, no significant alteration of immunomarkers for CIDP or IVIg-mediated immunomodulation was observed. Our exploratory study suggests that COVID-19 mRNA vaccine does not have a relevant impact on immune activity in CIDP. In addition, immunomodulatory effects of IVIg in CIDP are not altered by COVID-19 mRNA vaccine. This study was registered in the German clinical trial register (DRKS00025759). Overview over the study design. Blood samples of CIDP patients on recurrent IVIg treatment and vaccination with a COVID-19 mRNA vaccine were obtained at four timepoints for cytokine ELISA and flow cytometry, to assess key cytokines and cellular immunomarkers for disease activity and IVIg-immunomodulation in CIDP.

Status epilepticus and benzodiazepine treatment: Use, underdosing and outcome - insights from a retrospective, multicentre registry

OBJECTIVE

To explore the reasons for and outcomes of non- or undertreatment with benzodiazepines (BZDs) in status epilepticus (SE).

METHODS

We retrospectively analysed all SE patients from the urban area of Cologne over two years.

RESULTS

328 SE patients were eligible, and only 72% were initially treated with BZDs. Of these, only 21.6% were treated sufficiently with BZDs according to current guidelines. SE patients not initially treated with BZDs were significantly older, had less often known epilepsy, had a prolonged arrival time to the emergency room, and presented more often with a non-generalised convulsive semiology. Regarding adequate dosages, patients with a generalised convulsive SE seemed to benefit from a sufficient BZD dosing with significantly shortened mean ventilation duration (37.1 to 208 h), decreased mean intensive care unit (1.7 to 5 days) and in-hospital stay (4.1 to 8.8 days). In contrary, aggressive BZD treatment in non-generalised convulsive SE resulted in a longer inpatient stay (9.2 to 5.8 days) and lower favourable outcome rates at discharge (16% to 63%).

CONCLUSIONS

The current SE treatment guidelines for first-line BZD therapy in SE were violated in most patients. Sufficient BZD dosing was beneficial in generalised convulsive SE, but not in other forms of SE. SE semiology might be crucial for treatment decisions with BZDs. Further treatment evidence especially in non-generalised convulsive SE is urgently needed.

Repurposing MS immunotherapies for CIDP and other autoimmune neuropathies: unfulfilled promise or efficient strategy?

Despite advances in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and other common autoimmune neuropathies (AN), still-many patients with these diseases do not respond satisfactorily to the available treatments. Repurposing of disease-modifying therapies (DMTs) from other autoimmune conditions, particularly multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), is a promising strategy that may accelerate the establishment of novel treatment choices for AN. This approach appears attractive due to homologies in the pathogenesis of these diseases and the extensive post-marketing experience that has been gathered from treating MS and NMOSD patients. The idea is also strengthened by a number of studies that explored the efficacy of DMTs in animal models of AN but also in some CIDP patients. We here review the available preclinical and clinical data of approved MS therapeutics in terms of their applicability to AN, especially CIDP. Promising therapeutic approaches appear to be B cell-directed and complement-targeting strategies, such as anti-CD20/anti-CD19 agents, Bruton's tyrosine kinase inhibitors and anti-C5 agents, as they exert their effects in the periphery. This is a major advantage because, in contrast to MS, their action in the periphery is sufficient to exert significant immunomodulation.

Antibody response after COVID-19 vaccination in intravenous immunoglobulin-treated immune neuropathies

BACKGROUND AND PURPOSE

This study assessed the prevalence of anti-SARS-CoV-2 antibodies in therapeutic immunoglobulin and their impact on serological response to COVID-19 mRNA vaccine in patients with intravenous immunoglobulin (IVIg)-treated chronic immune neuropathies.

METHODS

Forty-six samples of different brands or lots of IVIg or subcutaneous IgG were analyzed for anti-SARS-CoV-2 IgG using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Blood sera from 16 patients with immune neuropathies were prospectively analyzed for anti-SARS-CoV-2 IgA, IgG, and IgM before and 1 week after IVIg infusion subsequent to consecutive COVID-19 mRNA vaccine doses and after 12 weeks. These were compared to 42 healthy subjects.

RESULTS

Twenty-four (52%) therapeutic immunoglobulin samples contained anti-SARS-CoV-2 IgG. All patients with immune neuropathies (mean age = 65 ± 16 years, 25% female) were positive for anti-SARS-CoV-2 IgG after COVID-19 vaccination. Anti-SARS-CoV-2 IgA titers significantly decreased 12-14 weeks after vaccination (p = 0.02), whereas IgG titers remained stable (p = 0.2). IVIg did not significantly reduce intraindividual anti-SARS-CoV-2 IgA/IgG serum titers in immune neuropathies (p = 0.69). IVIg-derived anti-SARS-CoV-2 IgG did not alter serum anti-SARS-CoV-2 IgG decrease after IVIg administration (p = 0.67).

CONCLUSIONS

Our study indicates that IVIg does not impair the antibody response to COVID-19 mRNA vaccine in a short-term observation, when administered a minimum of 2 weeks after each vaccine dose. The infusion of current IVIg preparations that contain anti-SARS-CoV-2 IgG does not significantly alter serum anti-SARS-CoV-2 IgG titers.

Versorgungssituation von CIDP-Patienten in neun deutschen Zentren des Neuritis Netzes

Hintergrund

Die Diagnose und Behandlung von Patienten mit immunvermittelten Polyneuropathien ist aufgrund der Heterogenität der Erkrankungen herausfordernd.

Ziel der Arbeit

Ein aktueller epidemiologischer Überblick über die Versorgungssituation von Patienten mit immunvermittelten Polyneuropathien innerhalb des deutschen Neuritis-Netzwerks „Neuritis Netz“.

Material und Methoden

Es erfolgte eine Umfrage in neun deutschen neurologischen Zentren, die auf die Betreuung von Patienten mit Immunneuropathie spezialisiert sind. Wir erfassten Diagnose, Vorgehen in der Diagnostik und Nachsorge, typische Symptome bei Manifestation und im Krankheitsverlauf sowie Therapiedaten.

Ergebnisse

Die Erhebung umfasst Daten von 1529 jährlich behandelten Patienten mit Immunneuropathien, 1320 davon mit chronisch inflammatorisch demyelinisierender Polyneuropathie (CIDP). Die Diagnostik umfasste fast immer Lumbalpunktionen sowie Elektroneuro- und -myografien entsprechend den aktuellen Leitlinien. Der Einsatz von Ultraschall, Biopsie und MRT war unterschiedlich. Wichtigster klinischer Parameter zum Therapiemonitoring in allen Zentren war die motorische Funktion in den klinischen Nachuntersuchungen. Zur Erhaltungstherapie wurde bei rund 15 % der Patienten ein breites Spektrum unterschiedlicher Immunsuppressiva eingesetzt.

Diskussion

Die Studie liefert wichtige epidemiologische Daten zur aktuellen Versorgungsituation von Patienten mit Immunneuropathien in Deutschland. Die Weiterentwicklung spezifischer Empfehlungen zur Therapie und Nachverfolgung von CIDP-Patienten ist notwendig, um einen einheitlichen Standard der Patientenversorgung zu gewährleisten. Dieses wird durch die strukturierte Zusammenarbeit von Exzellenzzentren wie dem deutschen Neuritis Netz erheblich unterstützt.

Status epilepticus during the COVID-19 pandemic in Cologne, Germany: data from a retrospective, multicentre registry

Background

The “coronavirus disease 2019” (COVID-19) pandemic, caused by the “severe-acute-respiratory-syndrome-coronavirus 2” (SARS-CoV-2), challenges healthcare systems worldwide and impacts not only COVID-19 patients but also other emergencies. To date, data are scarce on the extent to which the COVID-19 pandemic impacted status epilepticus (SE) and its treatment.

Objective

To assess the influence of the COVID-19 pandemic on the incidence, management and outcome of SE patients.

Study design

This is a retrospective, multicentre trial, approved by the University of Cologne (21-1443-retro).

Methods

All SE patients from the urban area of Cologne transmitted to all acute neurological departments in Cologne between 03/2019 and 02/2021 were retrospectively analysed and assessed for patient characteristics, SE characteristics, management, and outcome in the first pandemic year compared to the last pre-pandemic year.

Results

157 pre-pandemic (03/2019–02/2020) and 171 pandemic (from 03/2020 to 02/2021) SE patients were included in the analyses. Acute SARS-CoV-2 infections were rarely detected. Patient characteristics, management, and outcome did not reveal significant groupwise differences. In contrast, regarding prehospital management, a prolonged patient transfer to the hospital and variations in SE aetiologies compared to the last pre-pandemic year were observed with less chronic vascular and more cryptogenic and anoxic SE cases. No infections with SARS-CoV-2 occurred during inpatient stays.

Conclusions

SARS-CoV-2 infections did not directly affect SE patients, but the transfer of SE patients to emergency departments was delayed. Interestingly, SE aetiology rates shifted, which warrants further exploration. Fears of contracting an in-hospital SARS-CoV-2-infection were unfounded due to consequent containment measures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11260-2.

Chronic inflammatory demyelinating polyneuropathy and pregnancy: systematic review

Pregnancy largely affects disease activity and clinical course in women with immune-mediated neurological disorders. Chronic inflammatory demyelinating polyneuropathy (CIDP) is rare but the most common chronic immune-mediated neuropathy; however, the effects of pregnancy on CIDP have never been investigated except case reports or series. We here provide a systematic review of the literature from 1 January 1969 to 30 June 2020 that revealed 24 women with CIDP, who had onset or relapse during pregnancy. Of these, 17 (71%) developed CIDP during the first pregnancy, and 8 (47%) had a relapse during subsequent pregnancies. Of the 17 patients, in whom the CIDP subtypes were determined, all of them had typical CIDP. First-line treatments for CIDP, such as corticosteroids, immunoglobulin and plasma exchange were efficacious and safe. We suggest that pregnancy can trigger typical CIDP in some women, and women with CIDP have a higher risk of relapse during pregnancy. The onset or relapse of CIDP during pregnancy is a rare but challenging constellation for physicians.

Nerve conductions studies in experimental models of autoimmune neuritis: A meta-analysis and guideline

Nerve conduction studies (NCS) are essential to assess peripheral nerve fiber function in research models of immune-mediated neuritis. However, the current lack of standard protocols and reference values impedes data comparability across models and studies. We performed a systematic review and subsequent meta-analysis of the last 30 years of NCS of immune-mediated neuritis in Lewis-rats. Twenty-six papers met the inclusion criteria for meta-analysis. Extracted data showed considerable heterogeneity of recorded nerve conduction velocity (NCV) and compound muscle action potential (CMAP). Studies also significantly differed in terms of technical, methodical, and data reporting issues. The heterogeneity of the underlying studies emphasizes the need for standardization when conducting and reporting NCS in rats. We provide normative values for NCS of the sciatic nerve of Lewis rats and propose seven items that should be addressed when NCS are performed when studying immune paradigms in Lewis rats.

P630 Recovery of non-bacterial thrombotic endocarditis and severe aortic regurgitation in a young patient with acute promyelocytic leukemia

Introduction

Non-bacterial thrombotic endocarditis (NBTE) is characterised by non-infectious vegetations on the cardiac valves and is typically seen in patients with malignancies or systemic lupus erythematosus. Risk of thromboembolic events is high and treatment of choice consists of anticoagulation, if feasible, as well as treatment of the underlying disease. Severe valvular dysfunction is rarely seen and in these cases, surgical valve replacement is usually performed.

Case presentation

A 28-year old female patient presented with left-sided hemiparesis persisting for several hours. Angio-CT scan of the brain revealed a branch occlusion of the middle cerebral artery with a correlating infarct core and without an area of penumbra. Blood tests showed decreased thrombocyte levels (45 x109/l). Given the thrombocytopenia and the time between the onset of symptoms and presentation, no thrombolysis was administered.

A subsequently performed transoesophageal echocardiography for diagnostic work-up of cardioembolic sources of stroke revealed a right ventricular thrombus and vegetations on the aortic valve causing severe aortic regurgitation with a holodiastolic flow reversal in the descending aorta (Fig. 1 (a) and (b) showing a large central coaptation defect). There were no of signs of infection or inflammation and blood cultures remained negative, thus infectious endocarditis was unlikely. A bone marrow biopsy led to the diagnosis of acute promyeolocytic leukemia (PML). Despite the inherent high risk of bleeding due to PML, anticoagulation with unfractionated heparin was initiated and treatment with prednisolone, all-trans retinoic acid and arsenic trioxide was started. After three weeks of therapy aortic valve vegetation size decreased considerably leading to dramatic reduction of aortic regurgitation (Fig. 1 (c) and (d)). No further embolic event or bleeding occurred.

Conclusion

This case is remarkable in many aspects. First, PML typically causes bleeding complications whereas NBTE is characterised by a high risk of thromboembolic events. Thus, the decision to start or not to start anticoagulation is challenging.

Second, NBTE, unlike infectious endocarditis, rarely causes severe valvular dysfunction and reported treatment in most cases consisted of surgical valve replacement or repair. However, in this case, conservative treatment alone led to almost complete resolution of valvular vegetations and of aortic regurgitation.

We conclude that conservative treatment of severe valvular disease in the setting of NBTE should be strongly considered, especially given the small number of cases reported worldwide.

Abstract P630 Figure. Fig.1